ottstadt



(No Model.)

K. W. OTTSTADT & RWIRTH.

SAW.

,172. Patented Fe'b. 16",-1892.

WITNESSES:

UNITED STATES PATENT OFFICE. V

KARL \V. OTTSTADT, OF KOSTHEILWI, AND RICHARD WIRTH, OF FRANKFORT,

, GERMANY.

sAw.

SPECIFICATION forming part of Letters Patent No. 469,172, dated February 16, 1892.

Lpplication filed October 2,1889. Renewed September 24, 1891. Serial No.406,757. (No model.) Patentedin Germany August l9 1889, No. 51,932; in Switzerland August 20, 1889, No. 1,375; in France August 23, 1889, No. 200,367; in England August 26, 1889, No. 13,449; in Belgium March 10, 1890, No. 89,786, and in Austria-Hungary January 80, 1891,N0. 41,344 and No.

To all whom, it may concern.-

Be it known that we, KARL W. OTTsTADT, of Kostheim-on-the-Main, and RICHARD WVIR'rH, of Frankfort-on-the-lllain, Germany, both subjects of the Emperor of Germany, have invented a new and useful Improvement in Saws, (for which we have obtained Letters Patent in the following countries: in England, No. 13, 149, dated August 26, 1889'; in Germany,

10 No. 51,932, dated August 19, 1889; in Switzerland, No. 1,375, dated August 20, 1889; in France, No. 200,367, dated August 23, 1889; in Belgium, No. 89,786, dated March 10, 1890, and in Austria-Hungary, No. 41,344 and No.

67,598, dated January 30, 1891,) of which the following is a specification.

This invention relates. to saws for cutting angled or curved lines, as in slotting, recessing, dovetailing, &c., the transverse section of which saws is bent or curved to conform to that of the bent line to be cut and gradually enlarges from nothing at one end to the full size of the final cut at the other. These saws have heretofore been made single-that is, to

cut the bent line by starting at-one end and finishing at the,other-necessitating a construction of saw which was weak and liable to distortion when in use.

The object of our improvement is to pro- 0 vide a saw for such purposes which will out the slot or recess simultaneously from both ends of the bent outline of the same toward the middle, by which any form of slot or recess maybe cut by a single stroke, and a strong 5 and symmetrical construction of saw is obtained. I

The invention consists of a double saw of novel and peculiar construction, substantially as hereinafter describedand claimed.

Reference is to be had to the accompanying drawings, forming part of this specification, in which- Figure 1 represents a blank from which a saw embodying our invention is made. Fig.

2 is a side elevation of the said saw. Figs. 3,

4, 5, 6,7, 8, and 9 are transverse sections of the said saw on the lines 00 0;, y y, z z, o o, w w, r r, and s s,respect1ve1y.

The contour of the slot or recess to be cut, as in the edge of a board, being the same as the part of the saw-section (shown in Fig. 9) indicated by the letters I) c d e f g, the blank shown in Fig. 1 is formed of sheet or plate steel of a width equal to the total length of the contour b c d efg plus sufficient to form two non-cutting blade-bodies a h and divided medially, as from' the lower end to within a short distance of the other end, thereby forming two separate blades A B, integrally united, as at the upper end. The upper and lower ends of each blade are extended to form perforated lugs A A -and B B for attachment to the saw-holder. Lines of'teeth are cut on the inner edge of each blade, converging from the inner edges of the bladebodies a h, as at the lower ends, to a meeting at the upper ends, or preferably, as shown in Fig. 3, the line of teeth on one blade is extended past the end it of the line of teeth on the other, a space 19 being left for clearance. The whole blank is then bent transversely, so as to conform at every cross-section to the surface of a general cylinder having the crosssection a b c d efg h, as shown in Fig. 9, the blade-bodies a h being by preference in parallel planes and all the longitudinal elements of the blades and bodies, so far as they extend, being parallel to each other, as shown in Fig. 1. here the toothed edge takes a sharp turn, as at Z, a gap is preferably left to avoid cutting at different angles at the same time.

In operation the divided initial ends of the separate blades A B are brought simultane- I ously against the two terminals of the out line of the proposed slot, corresponding to the 85 saw-section b c d e f g,.aud the saw then drawn downward, when the parts of the slot outline corresponding to the parts 1) and g, c and f, and (l and e of the saw-section will be cut in such pairs in succession, a single downward stroke generally completing the entire slot, although in some cases a reciprocatory but gradually progressive motion of the saw may be necessary.

It is evident that double saws of this de- 5 scription may be made to cut on any desired 10 the blades bent transversely to 'conform at outline, while, being symmetrical and even-1y all points to the surface of a general cylinsustained at all points, they are not liable to der, substantially as described. distortion or breakage. In testimony whereof we have signed our We claim as our inventionnames to this specification in the presence of 5 4 A saw formed with two toothed blades, two subscribing witnesses.

which are separated laterally at one end and KARL W. OTTSTADT. united at the other end, the lines of teeth of I RICHARD WIRTH. which blades converge from the divided end I Witnesses: to a meeting or overlap at the other end, and FRANZ HASSLACHER,

J OSEPH PATRICK. 

